bcachefs: Fix memmove when move keys down

alanskind · Kent Overstreet · commit c522093b0283 · 2025-02-20T16:40:34.000-05:00
The fix alone doesn't fix [1], but should be applied before debugging that. [1] https://syzkaller.appspot.com/bug?extid=38a0cbd267eff2d286ff Signed-off-by: Alan Huang <mmpgouride@gmail.com> Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
diff --git a/fs/bcachefs/btree_io.c b/fs/bcachefs/btree_io.c
@@ -996,7 +996,7 @@ static int validate_bset_keys(struct bch_fs *c, struct btree *b,
 		}
 got_good_key:
 		le16_add_cpu(&i->u64s, -next_good_key);
-		memmove_u64s_down(k, bkey_p_next(k), (u64 *) vstruct_end(i) - (u64 *) k);
+		memmove_u64s_down(k, (u64 *) k + next_good_key, (u64 *) vstruct_end(i) - (u64 *) k);
 		set_btree_node_need_rewrite(b);
 	}
 fsck_err:

Original file line number	Diff line number	Diff line change
`@@ -996,7 +996,7 @@ static int validate_bset_keys(struct bch_fs c, struct btree b,`
`996`	`996`	`}`
`997`	`997`	`got_good_key:`
`998`	`998`	`le16_add_cpu(&i->u64s, -next_good_key);`
`999`		`- memmove_u64s_down(k, bkey_p_next(k), (u64 ) vstruct_end(i) - (u64 ) k);`
	`999`	`+ memmove_u64s_down(k, (u64 ) k + next_good_key, (u64 ) vstruct_end(i) - (u64 *) k);`
`1000`	`1000`	`set_btree_node_need_rewrite(b);`
`1001`	`1001`	`}`
`1002`	`1002`	`fsck_err:`